Our A/C tripped a circuit breaker. Found a 1,100 ohm ground on one hot line going to the outside unit. Opened it & the 3 wires to the compressor had 1,100 ohms. (Since the other hot line goes thru a relay that is open when the A/C unit is off, that explains why there was no 1,100 ohm ground at the breaker panel on that hot line.) So I cut the 3 wire plug boot to the comp. & that cleared all grounds.

Inspecting that rubber boot revealed oil & a grit that smells like gun powder. And on one side of that plug boot there is a melted a hole between a hot lead & the start capacitor connectors. Apparently a lighting strike?

It appears that the oily grit compound caused the 1,100 the ohm grounds for once the plug wires were cut the grounds were gone. And I cleaned the compressor terminals & measured them for grounds, none.

Being there is no evidence of oil leaking from the compressor on the unit or pan, would you:

Call in a HVAC tech now or crimp 3 female connectors to the wires to mate them back to the compressor terminals & try operating the A/C?

Do I need another plug boot?

And what is the oily grit in the plug boot that smells like gunpowder?
Is it an anti-arcing compound to prevent arcing between posts?

Thanks much,

Dave

Malcolm

07-26-2007 09:58 AM

Quote:

Originally Posted by DCK
(Post 54584)

In need of your expertise.

Our A/C tripped a circuit breaker. Found a 1,100 ohm ground on one hot line going to the outside unit. Opened it & the 3 wires to the compressor had 1,100 ohms. (Since the other hot line goes thru a relay that is open when the A/C unit is off, that explains why there was no 1,100 ohm ground at the breaker panel on that hot line.) So I cut the 3 wire plug boot to the comp. & that cleared all grounds.

Inspecting that rubber boot revealed oil & a grit that smells like gun powder. And on one side of that plug boot there is a melted a hole between a hot lead & the start capacitor connectors. Apparently a lighting strike?

It appears that the oily grit compound caused the 1,100 the ohm grounds for once the plug wires were cut the grounds were gone. And I cleaned the compressor terminals & measured them for grounds, none.

Being there is no evidence of oil leaking from the compressor on the unit or pan, would you:

Call in a HVAC tech now or crimp 3 female connectors to the wires to mate them back to the compressor terminals & try operating the A/C?

Do I need another plug boot?

And what is the oily grit in the plug boot that smells like gunpowder?
Is it an anti-arcing compound to prevent arcing between posts?

Thanks much,

Dave

When you check a compressor for ground, you need to pull the boot as you call it and check the terminals directly. You must have a copeland scroll compressor. You were probably getting a feedback reading since you still had the wires connected to other components. Try isolating parts to find ground problems.

DCK

07-26-2007 11:15 AM

Hi Malcolm,

Do appreciate your quick response.

Please read my post again for there are no grounds now that I have cut off the 3 wire female boot plug.

Those grounds were caused by an oily grit inside that plug that had shorted the compressor terminals & to the compressor itself. Either the damage was due to a lightning strike or the compressor went bad?

Since there was no oil anywhere else in the unit & the compressor terminals have no grounds, it is my opinion, which isn’t worth much, just ask my wife :(, that the compressor was hit by lightning & is still good?

The grit inside the boot smells like gunpowder.
Is that grit some type of anti-arching protection installed at the factory?
If so. is such compound required?

If yes, & since I’m going to have to buy another boot (the part # is: Cen-Elec DGS-1) because this one looks like one of my steaks:laughing:, what is the anti-arching compound called?

And if I’m correct that it was lightning damage, & the compressor is good in that the anti-arching compound(?) did its job, would you reconnect those 3 power leads, once I get a new boot plug, & try the A/C?

"You must have a copeland scroll compressor."

Looking into a mirror & reading backwards, & I have all I can do to read forwards:laughing:, it does appear that it is a Copeland compressor.

Sorry you are right. I didn't read your posts. Your posts are a little lengthy. I'll glance back over them.

Malcolm

07-26-2007 11:39 AM

OK... First thing first. Make sure you do not have any more grounds. Check the compressor directly from the terminals to the copper tubing or subsequent ground. You need to check all three terminals (runs, start and common). There isn't any compound that goes on the terminals. Are you sure it didn't blow a hole in the terminal plate. You will have no refrigerant if this is the case. I know it can be hard to see at the wrong angles. Check for a ground from the load side of the contactor (relay you were referring to and ground). Buy your new plug and connect it to your compressor. If you do not see a ground, turn it on and see what happens. Also, are you sure you were reading your ohm meter right. Some digital meters will read mega ohms and it tricks people into thinking they have a ground fault. Your breaker may have just tripped during the storm. If you have a ground, you will get continuity to ground. I have to admit I did just glance over your post the second time as well, so I may have missed something.

DCK

07-26-2007 03:06 PM

Hi Malcolm,

No offense intended for I do appreciate your help.

Please, thoroughly read my posts & you will know with certainty that there are NO grounds on the 3 terminals of the compressor at this time. I retired after driving a analog & digital vom for 40 years in telecommunications.

"There isn't any compound that goes on the terminals."

Thank you, sir.
"Are you sure it didn't blow a hole in the terminal plate. "

If by “terminal plate” you meant the location of where the 3 terminals lugs are found on the compressor, again, there is NO sign of oil escaping other than what little was found in the plug boot. If my 3 ton Coleman compressor holds more than 1 ounce of oil there is NO sign of the oil escape.

My Coleman is @ 5 years old.

Please correct me if the following statement is wrong.
I have been told that all recent A/C models have a low freon cut off feature. Is that true?

If it is then, without gauge(s), how does a person determine a low freon condition?

Many thanks.

Malcolm

07-26-2007 03:19 PM

Quote:

Originally Posted by DCK
(Post 54673)

Hi Malcolm,

No offense intended for I do appreciate your help.

Please, thoroughly read my posts & you will know with certainty that there are NO grounds on the 3 terminals of the compressor at this time. I retired after driving a analog & digital vom for 40 years in telecommunications.

"There isn't any compound that goes on the terminals."

Thank you, sir.
"Are you sure it didn't blow a hole in the terminal plate. "

If by “terminal plate” you meant the location of where the 3 terminals lugs are found on the compressor, again, there is NO sign of oil escaping other than what little was found in the plug boot. If my 3 ton Coleman compressor holds more than 1 ounce of oil there is NO sign of the oil escape.

My Coleman is @ 5 years old.

Please correct me if the following statement is wrong.
I have been told that all recent A/C models have a low freon cut off feature. Is that true?

If it is then, without gauge(s), how does a person determine a low freon condition?

Many thanks.

No, that is not true. You must be thinking of automotive air conditioner.

DCK

07-26-2007 03:34 PM

"No, that is not true. You must be thinking of automotive air conditioner."

Thank you, sir.

Now to the next question.

"Are you sure it didn't blow a hole in the terminal plate. "

If by “terminal plate” you meant the location of where the 3 terminals lugs are found on the compressor, again, there is NO sign of oil escaping other than what little was found in the plug boot.

If my 3 ton Coleman compressor holds more than 1 ounce of oil there is NO sign of the oil escape.

How much oil is there in a 3 ton compressor?

Thanks

Malcolm

07-26-2007 04:13 PM

Quote:

Originally Posted by DCK
(Post 54679)

"No, that is not true. You must be thinking of automotive air conditioner."

Thank you, sir.

Now to the next question.

"Are you sure it didn't blow a hole in the terminal plate. "

If by “terminal plate” you meant the location of where the 3 terminals lugs are found on the compressor, again, there is NO sign of oil escaping other than what little was found in the plug boot.

If my 3 ton Coleman compressor holds more than 1 ounce of oil there is NO sign of the oil escape.

How much oil is there in a 3 ton compressor?

Thanks

If it blew a hole you would have a lot of oil at the bottom of the unit. If you aren't showing a short to ground, wire it up and test it. I think you are over diagnosing the problem. Here is how I would have tested the unit.

- Checked the breakers. If it was tripped, I would reset the breaker and see what happens. If it trips immediately, I would go to the unit the breaker is feeding.

- I usually check the load side of the contactor to see if I am showing a ground. If I am showing a ground, I will isolate each electrical component and test it. I usually start with the compressor.

- I would have pulled the terminals off the compressor and tested for a short to ground. If it is showing a short, it would be time for a new compressor. If not I would move to other components. I have found crankcase heaters to electrical whips shorted.

Since you no longer have a short, there is no reason to keep trying to diagnose anything. I would need to turn the unit on to see if the refrigerant levels are OK. This is assuming that it didn't blow its charge.

DCK

07-26-2007 05:35 PM

"If it blew a hole you would have a lot of oil at the bottom of the unit."

As mentioned several times previously there is no evidence of oil.
Thank you, sir.

"If you aren't showing a short to ground, wire it up and test it."

Not yet as I do not have gauges.

That is why (to you) I'm “over diagnosing”.

"Checked the breakers. If it was tripped, I would reset the breaker and see what happens. If it trips immediately, I would go to the unit the breaker is feeding."

Exactly what I did, & that is when I found the grounds on the compressor.

"I usually check the load side of the contactor to see if I am showing a ground. If I am showing a ground, I will isolate each electrical component and test it. I usually start with the compressor."

Testing is a matter of preference & acquired knowledge from previous experience working on different mfgr’s equip. Each mfgr has its particular quirks/troubles. It took me less than 10 minutes to isolate the problem & half a day trying to get a straight answer.

Good day, sir.

Malcolm

07-26-2007 06:11 PM

Quote:

Originally Posted by DCK
(Post 54695)

"If it blew a hole you would have a lot of oil at the bottom of the unit."

As mentioned several times previously there is no evidence of oil.
Thank you, sir.

"If you aren't showing a short to ground, wire it up and test it."

Not yet as I do not have gauges.

That is why (to you) I'm “over diagnosing”.

"Checked the breakers. If it was tripped, I would reset the breaker and see what happens. If it trips immediately, I would go to the unit the breaker is feeding."

Exactly what I did, & that is when I found the grounds on the compressor.

"I usually check the load side of the contactor to see if I am showing a ground. If I am showing a ground, I will isolate each electrical component and test it. I usually start with the compressor."

Testing is a matter of preference & acquired knowledge from previous experience working on different mfgr’s equip. Each mfgr has its particular quirks/troubles. It took me less than 10 minutes to isolate the problem & half a day trying to get a straight answer.

Good day, sir.

A lot of people do not even notice the oil at the bottom of the unit. That is why I told you to see if there was any oil. You kept stating that there was a little on the plug. Why do you need gauges at this point? You are trying to see if you figured out the problem. I'm assuming there wasn't any problem with the unit up until the breaker tripped. Well, get the unit running and then you can find gauges if you want and check the pressures. That is why I say you are over diagnosing. The electrical circuit and refrigerant circuit are two different things. Get the first thing working before you start tinkering with something else. If you had a bad distributor on your car, would you start diagnosing the brakes or the head lights? No, you would start the car. Well, start your air conditioner.

Quote:

Testing is a matter of preference & acquired knowledge from previous experience working on different mfgr’s equip.

I do agree it is a matter of preference, but you obviously didn't do it correctly. Otherwise, you wouldn't have to go buy another plug. I'm just trying to help you buddy. If you know everything, why did you come here for? There isn't any manufacturer specific way to troubleshoot a short to ground LOL. I try and give help the best I can, but I try to keep my time spent responding to questions to a minimum. Otherwise, one could spend a half day on a forum like you did. I just glance over the posts and give a general overview of how I would diagnose the problem. It is up to the OP to see if they diagnosed it the same way. Sorry, I didn't give you the straight answer you were looking for, but to be frank, I could care less. If you want a straight answer, go pay an HVAC technician to come out to your house instead of breaking parts. I would call a pro for the refrigerant. You are supposed to be EPA certified and plus you wouldn't know what was going on anyways. I would turn it on. If it runs and you feel cold air coming out of the vents, then you know you are back to square one before the incident. It is highly unlikely that your unit developed a short and contemporaneously lost a little refrigerant. You are looking for other problems when you say you already fixed the problem. You can have your refrigerant levels checked at your next tune up.

You have a good day too.

DCK

07-26-2007 07:57 PM

"I do agree it is a matter of preference, but you obviously didn't do it correctly. Otherwise, you wouldn't have to go buy another plug."

:laughing:There have been 5 people that have seen this plug & not one of them told me that I had ruined a perfectly good boot plug. :laughing:
taken from my first post.

Inspecting that rubber boot revealed oil & a grit that smells like gun powder. And on one side of that plug boot there is a melted hole between a hot lead & the start capacitor connectors. Apparently a lighting strike?

"I'm just trying to help you buddy."

OK & I thank you, but you must learn to comprehend what has been repeatedly given to you. I state that not to “flame” you but to help.

"If you know everything, why did you come here for?"

No sir I don't. Remember this (taken from the first line of my first post)?
“In need of your expertise.“

Now read all of that first post & consider this as my reply to you with the situation reversed.

(Hi Malcolm,

Can’t say whether it was lightning or a shorted connection but there is no anti-arcing compound in compressor boot plugs. If you got oil & grit in yours it could have been dirt dobbers? But since you have cleared the grounds & see no evidence of oil, there is a possibility that the compressor is still good, so try this.

1.) Crimp those 3 wires with female connectors & put them back on their respective terminals on the compressor.
2.) Turn on the A/C breakers & check a register, it should be blowing cooler air in 3 minutes.
3.) If not shut the A/C off & call in the pro’s.
4.) But if the air gets cooler in 3 minutes then get a temp gauge up to that register & the temp should drop approximately __X__ degrees in __X__ minutes.

If the temp is dropping like that then it looks like you may have dodged a bullet.

Good day.)

Malcolm, how much space & time did that take?

And did you note it was just took one post?

"I would turn it on. If it runs and you feel cold air coming out of the vents, then you know you are back to square one before the incident."

Thank you, sir. I will do that just do not know how long to wait. The HVAC folk @ here are booked up to their eyeballs so it will be awhile before they can get to me.

Take care, Malcolm.

Malcolm

07-26-2007 09:04 PM

Quote:

Originally Posted by DCK
(Post 54717)

"I do agree it is a matter of preference, but you obviously didn't do it correctly. Otherwise, you wouldn't have to go buy another plug."

:laughing:There have been 5 people that have seen this plug & not one of them told me that I had ruined a perfectly good boot plug. :laughing:
taken from my first post.

Inspecting that rubber boot revealed oil & a grit that smells like gun powder. And on one side of that plug boot there is a melted hole between a hot lead & the start capacitor connectors. Apparently a lighting strike?

"I'm just trying to help you buddy."

OK & I thank you, but you must learn to comprehend what has been repeatedly given to you. I state that not to “flame” you but to help.

"If you know everything, why did you come here for?"

No sir I don't. Remember this (taken from the first line of my first post)?
“In need of your expertise.“

Now read all of that first post & consider this as my reply to you with the situation reversed.

(Hi Malcolm,

Can’t say whether it was lightning or a shorted connection but there is no anti-arcing compound in compressor boot plugs. If you got oil & grit in yours it could have been dirt dobbers? But since you have cleared the grounds & see no evidence of oil, there is a possibility that the compressor is still good, so try this.

1.) Crimp those 3 wires with female connectors & put them back on their respective terminals on the compressor.
2.) Turn on the A/C breakers & check a register, it should be blowing cooler air in 3 minutes.
3.) If not shut the A/C off & call in the pro’s.
4.) But if the air gets cooler in 3 minutes then get a temp gauge up to that register & the temp should drop approximately __X__ degrees in __X__ minutes.

If the temp is dropping like that then it looks like you may have dodged a bullet.

Good day.)

Malcolm, how much space & time did that take?

And did you note it was just took one post?

"I would turn it on. If it runs and you feel cold air coming out of the vents, then you know you are back to square one before the incident."

Thank you, sir. I will do that just do not know how long to wait. The HVAC folk @ here are booked up to their eyeballs so it will be awhile before they can get to me.

Take care, Malcolm.

I'm not reading that. Why do you keep writing essays? I'm trying to replace my roof and I just check the roofing forum every once and a while. I just popped my head in the HVAC forum to see what kind of posts titles were posted. I'm sorry I ever opened yours you ungrateful @%&#. Stick to communications and stop thinking you are a jack of all trades. If you don't like my responses, read all the other replies you got. I told you how I was responding you idiot. I don't listen to DIY troubleshooting techniques because they give you wrong info and screw up my diagnosis. Do you know how many times I walk into a house and the customer says it is the t-stat that is the problem. Do I just take their word for it or do I troubleshoot the problem my way? It has never been the t-stat by the way. Some people say it is shorted to ground, but it really isn't. I could tell you know absolutely nothing about what you are doing because you aren't calling things by their proper names. I don't have time to ask how you tested it. I just let them know the procedure for diagnosis and help them if they get stuck. The "plug" may have needed to be replaced, but obviously, the 5 people you asked don't have any HVAC experience you idiot. I read one of your other posts about a burnt plug on a refrigerator. You thought it was caused by splitting an outlet. Man, stay away from electricity before you kill yourself you incompetent #*($.

elementx440

07-27-2007 01:43 AM

Quote:

Originally Posted by Malcolm
(Post 54731)

Man, stay away from electricity before you kill yourself you incompetent #*($.